Process more data if seen in LMTP

Same fix as was done for SMTP reported in #9014 (commit e9a898d2)

Fixes CPAN bug #47666: Ignored QUIT with LMTP PIPELINING
Merge pull request #4 from mcsnolte/47666_ignored_quit_with_lmtp_pipelining

Process more data if seen in LMTP